“Cooperation with farmers is essential”

Safe drinkable water when opening the tap. What is taken for granted today may no longer be in the future. Because an increasing demand for drinking water in combination and intensified by climatic changes risks endangering the supply, at least at times. “Climate change poses major challenges for water management”, says the national Strategy and Action Plan for Adaptation to the Effects of Climate Change. The government’s strategy paper for the period from 2018 to 2023 identifies the expected climatic impacts on a variety of sectors and specifies how the country can prepare.

In particular, this means that even successfully limiting global warming to 1.5 degrees in accordance with the Paris Climate Agreement will have certain effects. “Data from Meteolux and the Luxembourg Institute of Science and Technology show that average temperatures are already higher today than in previous decades”, says Bruno Alves from the Ministry of Environment, Climate and Sustainability. The consequences include more frequent tropical nights (with temperatures above 20°C), periods of drought or rising water temperatures. Higher temperatures lead to additional water consumption, whether in nature due to the natural vegetation season or due to human activities such as watering plants or filling swimming pools.

Precipitation is also impacted. “We don’t see much difference in the long-term values, but in the past decade we were below the average amount seven times”, Alves elaborates. Not only was there less rain overall in those years, but there was more precipitation instead of snow in winter, and less rain in summer — but more heavy rainfalls and tempests. “This has an impact on the entire environment.”

Groundwater levels are regenerating even less as a result. Reserves are normally replenished in winter. This works best with snow, because depending on the degree of saturation of the soil, it seeps into the ground more slowly. However, higher temperatures also lead to extended vegetation seasons and greater evaporation. Which means the plants draw water from the soil for longer than usual. Half of the drinking water supply in Luxembourg is groundwater. According to Tom Schaul from the Ministry of the Environment, groundwater reserves are currently about 25 per cent below the 30-year average.

In view of these challenges, the government is relying on a three-pillar-strategy: Saving water, tapping new resources — with the possible scenario of treating water from the Moselle — and protecting existing resources. But how does this protection work in practice? This can be illustrated by two very different examples, which at their core, face the same challenges.

A mammoth task in the reservoir region

The reservoir water passes through two-metre-high quartz sand filters before it is disinfected with chlorine. After a total of five steps, it is treated and ready for its long journey across the country. From the treatment plant of the ‘Syndicat des Eaux du Barrage d'Esch-Sur-Sûre’ (SEBES), the water is pumped into the main tank in Eschdorf and from there it reaches customers such as the ‘Syndicat des Eaux du Sud’ (SES) via a distribution network of 175km. Anyone who turns on the tap in the south-west of the country gets a strictly inspected cocktail of water from springs, wells and SEBES.